Studied systems

The Moëze-Oléron National Nature Reserve

Figure 1: The Moëze-Oléron National Nature Reserve on the mainland side (photo: Romain Beaubert, LPO).

Studied systems

The Moëze-Oléron National Nature Reserve

Figure 2: The Moëze-Oléron National Nature Reserve on the mainland side (photo: Romain Beaubert, LPO).

Studied systems

The Moëze-Oléron National Nature Reserve

Figure 3: The Moëze-Oléron National Nature Reserve on the mainland side (photo: Romain Beaubert, LPO).

Studied systems

The Eurasian curlew

Figure 4: Eurasian curlew (Numenius arquata, photo: Armel Deniau, LPO).

Studied systems

The GPS tracking

Figure 5: GPS equipment on an Eurasian curlew (photo: Loic Jomat, LPO).

Objectives of the study

Identify and propose local priority areas to be preserved for the protection of wading birds, as the Eurasian curlew as flagship species.

Understand how the Eurasian curlew uses space in a functional site comprising the Marennes basin and the Brouage marshes, in a context maritimization and strong anthropogenic pressures (hunting, shellfish gathering, oyster farming).

Studied area

Figure 6: Studied area split into three main zones A, B and C. The red pin is the fieldwork station.

GPS data

Figure 7: GPS tracking period for each indivdual

80 individuals

36 females, 39 males, 7 unknown

20 juveniles, 60 adults

= 2,226,199 studied GPS points

Behaviors attribution - Methods

The GPS recorded points are associated with a behaviors :

foraging, roosting and other.


Foraging:

a stationary point 2h before or after a low tide.


Roosting:

a stationary point 2h before or after a high tide.

Photo: Tareq Uddin Ahmed
Photo: Laurie Campbell

Space use analyses - Methods

Main used area estimated with Utilization Distribution (UD) function and the kernel method.

The bandwidth parameter h has been fixed for each analyses as the half the estimated Silverman rules values (depending on the variance in latitude and longitude locations) for a fine-grained scale details (functions kernelUD and getverticeshr from the R package “adehabitatHR”, Calenge 2006, and see Worton, 1995)

Foraging area

The foraging areas are estimated using Utilization distribution kernel function on the foraging points of all the individuals.

Figure 8: Foraging zone A
Figure 9: Foraging zone B
Figure 10: Foraging zone C

Roosting area

The roosting areas are estimated using Utilization distribution kernel function on the roosting points of all the individuals.

Figure 11: Roosting zone A
Figure 12: Roosting zone B
Figure 13: Roosting zone C

Roosting-foraging distance - Methods

The mean distance between the foraging and roosting areas of each individual was estimated as the mean distance between pairs of individual geographic centroids for their foraging and roosting areas at each tide cycle.

Figure 14: Estimating mean distance (+/- standard error) between roosting and foraging areas for each individual.

Roosting-foraging distance - Methods

The mean distance between the foraging and roosting areas of each individual was estimated as the mean distance between pairs of individual geographic centroids for their foraging and roosting areas at each tide cycle.

Figure 15: Estimating mean distance (+/- standard error) between roosting and foraging areas for each individual.

Roosting-foraging distance - Methods

The mean distance between the foraging and roosting areas of each individual was estimated as the mean distance between pairs of individual geographic centroids for their foraging and roosting areas at each tide cycle.

Figure 16: Estimating mean distance (+/- standard error) between roosting and foraging areas for each individual.

Roosting-foraging distance - Methods

The mean distance between the foraging and roosting areas of each individual was estimated as the mean distance between pairs of individual geographic centroids for their foraging and roosting areas at each tide cycle.

Figure 17: Estimating mean distance (+/- standard error) between roosting and foraging areas for each individual.

Roosting-foraging distance - Methods

The mean distance between the foraging and roosting areas of each individual was estimated as the mean distance between pairs of individual geographic centroids for their foraging and roosting areas at each tide cycle.

Figure 18: Estimating mean distance (+/- standard error) between roosting and foraging areas for each individual.

Roosting-foraging distance

Figure 19: Individual mean roosting-foraging distance (+/- standard error).

Roosting-foraging distance

Figure 20: Individual mean roosting-foraging distance (+/- standard error) as a function of sex age and the tide height.